With Central Power Source Patents (Class 379/176)
  • Patent number: 11720318
    Abstract: An audio accessory with high and low impedance paths to a speaker is provided, and a radio therefor. The audio accessory comprises: a speaker; an audio interface to connect to a respective audio interface of the radio; a switching circuit comprising: high and low impedance paths; and a switch to connect the audio interface to the speaker via one of the high and low impedance paths, the switch initially connecting the audio interface to the speaker via the high impedance path. The accessory further comprises a data interface to connect to a respective data interface of the radio; and a controller to: in response to receiving, via the first data interface, from the radio, a message to control the switch to connect the audio interface to the speaker via the low impedance path, control the switch to connect the audio interface to the speaker via the low impedance path.
    Type: Grant
    Filed: December 17, 2021
    Date of Patent: August 8, 2023
    Assignee: MOTOROLA SOLUTIONS, INC.
    Inventors: Joo Yih See, Daniel Grobe Sachs, Heng Leong Leong, Robert A. Zurek, Sheau Wei Ch'Ng
  • Patent number: 7964993
    Abstract: Embodiments disclosed herein describe a network device including a class AB common mode suppression (CMS) circuit coupled in parallel between a line voltage source and a physical layer (PHY) device that provides active EMI suppression and Phy device termination. A network connector is coupled to provide the line voltage source to the class AB CMS circuit. The class AB CMS circuit provides current to the PHY device, terminates open-drain transmit drivers of the PHY device and suppresses common mode noise thereby minimizing electromagnetic interference. In other embodiments, the class AB CMS circuit is coupled in parallel between the network connector and a physical layer (PHY) device. The class AB CMS circuit suppresses common mode noise, and terminates open-drain transmit drivers of the PHY device, thereby minimizing electromagnetic interference.
    Type: Grant
    Filed: March 6, 2007
    Date of Patent: June 21, 2011
    Assignee: Akros Silicon Inc.
    Inventors: Jun Cai, Amit Gattani
  • Publication number: 20040124996
    Abstract: This invention relates to data communication equipment (DCE), more specifically, high speed transmission of electronic data between data terminal equipment (DTE). The invention sets forth a method and a device for transmitting a voltage signal waveform as a series of current pulses onto, for instance, a communication line. The method requires converting an input voltage signal waveform to a current signal waveform and transmitting the resulting current pulses onto a communication line wherein a predetermined bias voltage is maintained.
    Type: Application
    Filed: November 6, 2003
    Publication date: July 1, 2004
    Inventor: James Andersen
  • Publication number: 20030072425
    Abstract: Call detail records are generated for usage of a telecommunications service established in a telecommunications network, by monitoring messages in a signalling system for co-ordinating operation of the network and carried over signalling links in the signalling system between a service switching function entity and a service control function entity. Messages are selected that relate to instances of usage of the telecommunications service initiated by the service switching function entity to at least one signal switching point in the network. These selected messages are correlated in accordance with the usage instance to which they relate, and information in the correlated selected messages is used to derive a call detail record for an instance of usage of the telecommunications service.
    Type: Application
    Filed: September 4, 2002
    Publication date: April 17, 2003
    Applicant: Agilent Technologies, Inc.
    Inventor: Michael Hurst
  • Patent number: 5781622
    Abstract: An apparatus for providing an intercom function on a telephone, without the need for an external power supply, having DTMF or pulse capabilities including an intercom operation device arranged for connection to a DTMF or pulse telephone line and to a DTMF or pulse telephone instrument. The apparatus includes a device for sensing an extension selection dual input from the DTMF or pulse telephone instrument and transmitting a corresponding extension address signal over the DTMF or pulse telephone line. Also included is an apparatus for sensing a received extension address signal from the telephone line, determining whether it corresponds to the telephone instrument to which the intercom operation apparatus is connected and, upon determination of correspondence, providing an extension selection ring output.
    Type: Grant
    Filed: May 5, 1995
    Date of Patent: July 14, 1998
    Inventor: Kornizer Ben-Zion
  • Patent number: 5428388
    Abstract: A communication apparatus for monitoring sounds and images at a remote location, such as the entranceway of a dwelling or other building includes a sensor station located at the entranceway, and a monitor station located within the building. A microphone and television camera in the sensor station modulate signals, preferably of radio frequency, emitted by a wireless transmitter in the sensor station. The monitor station includes a transmitter and demodulator for reproducing sounds and visual images received by the sensor station. Preferably, the monitor station contains a microphone and transmitter for transmitting voice signals from the monitor station to the sensor station, in which case, the sensor station contains a receiver and loudspeaker for reproducing the voice signals.
    Type: Grant
    Filed: June 15, 1992
    Date of Patent: June 27, 1995
    Assignee: Richard von Bauer
    Inventors: Richard P. von Bauer, Douglas W. Eberlen
  • Patent number: 5148468
    Abstract: A door answering system is described for enabling the occupant of a structure (e.g., house, apartment, etc.) to provide a pre-recorded message to a visitor who has approached the entrance of the structure. The system includes a speaker/microphone and a call switch at the entrance for the visitor. Inside the structure there is a recorder/player for playing a pre-recorded message and recording a message left by the visitor.
    Type: Grant
    Filed: October 24, 1990
    Date of Patent: September 15, 1992
    Inventors: Paul J. T. Marrick, Gregory J. Arnold, Rudolph A. Sauter
  • Patent number: 5040207
    Abstract: A two-telephone intercom has a simple station-call signalling system. In the preferred embodiment, each telephone is provided with its own respective signalling unit comprising (a) a dc voltage source, (b) a voltage-sensitive threshold element (preferably, a zener diode), and (c) a signalling device, e.g., a beeper and/or flashing light. Whenever one of the telephones is activated (i.e., taken off hook), the signalling device associated with the other telephone becomes operative and remains operative until the other telephone is answered (i.e., activated) or until the first telephone is hung up. Three embodiments of the signalling-unit circuits are disclosed.
    Type: Grant
    Filed: September 4, 1990
    Date of Patent: August 13, 1991
    Inventor: Buckminster G. Stein
  • Patent number: 4741031
    Abstract: An intrinsically safe telephone as provided for use in hazardous areas. The telephone includes a single line instrument located in the hazardous area which, in turn, is coupled by a two-wire transmission path to a shunt diode barrier and a telephone line interface located in a safe environment. The telephone line interface reduces power of incoming ringing and audio signals. The telephone line interface further includes an off hook indicating circuit which senses when the single line instrument is off hook. The telephone line interface further includes a bootstrap power supply for powering the single line instrument whenever the single line instrument is off hook. The intrinsically safe telephone is line powered and requires no auxiliary power in the hazardous environment. The intrinsically safe telephone is useful in all hazardous environments as classified by the National Electrical Code and requires no explosion-proof housing.
    Type: Grant
    Filed: June 27, 1986
    Date of Patent: April 26, 1988
    Assignee: Gai-Tronics
    Inventor: Larry P. Grandstaff
  • Patent number: 4716584
    Abstract: A terminal station operating with a current supplied from a master station exchanges signals with it through cable conductors, one of the cable conductors being grounded at the master station to allow the current to return from the terminal station. A receive circuit is formed by a first differential amplifier and a first resistor network connected in a balanced relationship to input terminals of the first differential amplifier for receiving a signal from the master station in a noise-cancelling relationship with respect to the ground potential to eliminate the effect of noise generated by the passage of the current through the ground conductor.
    Type: Grant
    Filed: May 23, 1986
    Date of Patent: December 29, 1987
    Assignee: NEC Corporation
    Inventor: Hisashi Fujisaki